Fig. 3. Granulosa cells influence oocyte pH_i in cumulus-oocyte complexes. (A) Example of an experiment in which cumulus-enclosed and denuded oocytes were compared with SNARF-dextran. Brightfield (left) and fluorescence (right) images are shown. (B) Cl^- was removed from the bath at 10 minutes. (C,D) Cumulus-enclosed oocytes exhibited a significantly higher resting pH_i (C; P<0.05) and rate of pH_i increase (D; P<0.01) than did denuded oocytes. Data are from four replicates. Total oocytes: denuded, n=25; cumulus-enclosed, n=23.